Vending machines have always served the purpose of providing an around-the-clock shopping alternative, but until recently, the quantity and assortment of items has been limited. Small packages of cigarettes, candy, beverages, and snack foods have traditionally made up over 90% of all vended products. Vending machines allow retailers to offer products for sale without the necessity of a clerk or cashier present in locations where it is not physically possible or economically sensible to establish a store. Vending machines offer the consumer quick and convenient access to products around-the-clock.
Over the years, vending machines have been designed and constructed to deliver a specific item or a small range of items. Generally, the products vended were relatively small and uniform in size and were dispensed by gravity feed to a customer access area. Alternative delivery systems, which could handle a variety of product sizes, moved the products into alignment with a customer access door.
Convenience is a driving factor in consumer's decisions where to purchase goods and services, and they want speed and efficiency in performing basic tasks so that they have more leisure time. Providing a large variety of products required for daily living in a vending machine where the consumer lives, works, or plays, and delivering them without damage, would satisfy consumer demand for more convenient shopping. However, the number, variety, and differing size of articles requires a vending machine capable of individualized handling of the articles. Several prior art systems have been developed to deliver articles from shelving to a customer access area. Generally the articles are arranged on vertically stacked shelves with individual article types separated into rows. Thus, a matrix of accessible articles is formed. Articles are ordered through input devices which also have associated devices to charge for the purchase. Generally, credit cards, debit cards, and cash are accepted. The location of each article is provided to an electronic controller, typically a microprocessor, which directs the retrieval of the articles by a transporter system.
In U.S. Pat. No. 3,294,282 Brown discloses storage of articles between parallel adjustable spaced guide rails on each vertically stacked shelf. To retrieve an article an elevator rises to the appropriate shelf level. The selected article is moved by a motor driven tape which pushes the end article in a row onto the elevator. The elevator surface is itself a conveyor belt which moves the article to a delivery platform at one end of the elevator. The elevator then lowers so that the delivery platform is adjacent a customer delivery access door. One article at a time can be delivered. Different articles are accommodated either on different levels or in different racks on the same levels if separate drive tapes are provided.
In U.S. Pat. No. 4,108,333 endless conveyor belts running rear to front on each shelf support the articles to be dispensed. Multiple belts may be located on each shelf. An elevator which is as wide as the shelves is moved vertically. The elevator has a bottom which is inclined downwardly rear to front forming a gentle slope with a stopping barrier at its lowermost edge. The elevator can swing through a small arc and is held upright for vertical travel. A spring bias permits the elevator mechanism to detent at the selected level to stop. The elevator is swung slightly towards the shelf so that its rear edge is closely adjacent the forward end of the conveyor belt and the elevator engages a clutch which activates the conveyor belt. Articles are dispensed onto the elevator by the movement of the conveyor belt. On the elevator articles slide down the inclined bottom until stopped. The elevator then returns to the customer access area. A sensor which detects articles on the elevator may be used to lock further elevator movement until the article is removed.
For a vending machine designed to heat and deliver food, Friberg in U.S. Pat. No. 4,762,250 discloses a carriage which is moved vertically and laterally by motor drive screw spindles so that a tilted chute is aligned with the edge of a storage shelf adjacent the row of a selected item. A pusher mechanism propels the item off the end of the shelf so that it slides down the chute to a stop. The carriage returns to a delivery position where the article is deposited on a shelf and subsequently moved into a microwave oven cavity. After heating, the article is delivered to a customer access door.
To dispense video cassettes, O'Neil, in U.S. Pat. No. 4,812,629, teaches arranging the cassettes in specialized boxes stored in a 2D array in which only one box occupies each matrix position. Horizontal and vertical motors move a carriage into alignment with each position. On the carriage grasping fingers located on a shuttle belt engage a bar on the special cases. Movement of the belt withdraws the cassette onto the carriage which then returns to position opposite a customer access door.
For a kiosk designed to dispense a large number of non-uniformly packaged goods, Steury discloses in U.S. Pat. No. 5,499,707 a carriage driven by X-Y drive motors to a point opposite an appropriate article-containing drawer on a shelf. Specialized drawers, sized to the article to be dispensed, have no bottoms and dividers to separate the articles in each drawer. An electromagnet on the carriage engages a steel plate on the drawer and pulls the drawer out from the edge of the shelf. Articles in the drawer fall into the carriage receptacle. The control electronics withdraw the drawer a distance sufficient to obtain only the number of items needed. Several items can be obtained from different drawers before the carriage is returned to a customer accessible door.
A room sized vending machine capable of storing a large variety of differently sized articles is disclosed by Kanatsuka in U.S. Pat. No. 5,791,512. Again, articles are arranged in rows from front to back on a matrix of shelves. Each shelf is tilted downward at its front so that the articles slide against a stop at the lowest position of the shelf. A bucket is moved by X-Y motors across the array until opposite a selected item. Actuation of a motor on the bucket presses a stopper on the shelf which releases one article into the bucket. Additional articles are prevented from sliding off the shelf by a second stopper which is simultaneously inserted behind the article being dispensed. Several articles may be dispensed into the bucket before the bucket returns to a customer access area where the items are dropped into the access area by the opening of a bottom plate in the bucket.